Miniature wave guide switch



Nov. 14, 1961 D. H. LANCTOT MINIATURE WAVE GUIDE SWITCH Filed April 2, 1959 2 Sheets-Sheet 1 lo u 2| I /NVE/VTOR. DONALD H. 'LANC'IUI' Nov. 14, 1961 D. H. LANCTOT 3,009,117

MINIATURE WAVE GUIDE SWITCH Filed April 2, 1959 2 Sheets-Sheet 2 as 44 I l 42 I 35 43 #vvmroe DONALD H7.0LANCTOT am a MW 5 ATTORNEYS United States Pater 3,009,117 MINIATURE WAVE GUIDE SWITCH Donald H. Lanctot, Malibu, Calif, assignor to Don-Lari Electronics Co., Inc., a corporation of California Filed Apr. 2, 1959, Ser. No. 803,635 8 Claims. (Cl. 333-7) This invention relates generally to ultra high frequency switching components and more particularly to an improved miniaturized wave guide switch.

Switching devices for transferring high frequency electromagnetic energy between various wave guides have been provided heretofore and find wide applications in radar systems. In airborne equipment, it is extremely important that such switches be of minimum size and weight. Moreover, it is desirable that these switches be capable of operation from remote locations.

With respect to the physical construction of the switch itself, minimum power loss between connected wave guide passages and maximum isolation between disconnected passages is of the utmost importance. A further desirable feature is to provide means within the switch body for terminating a disconnected wave guide passage in substantially its characteristic impedance so that undesirable reflections are avoided.

With respect to remote operation of the switch, it is not only desirable to enable switching to take place under power, but also to provide a structure in which very little power is required to effect the switching operation.

With the foregoing considerations in mind, it is a primary object of the present invention to provide an improved miniaturized wave guide switch in which electromagnetic energy may be transferred from one wave guide passage to another and in which the switch body itself is of minimum size and mass for effecting this operation.

Another object is to prow'de a miniature wave guide switch exhibiting minimum power losses between connected passages and maximum isolation between disconnected passages and in which the switching component itself includes means for terminating disconnected passages in substantially their characteristic impedances.

Other important objects are to provide a wave guide switch of compact symmetrical design to the end that entrance and exit passages are less than a wave length apart and the switching element itself is of extremely short electrical length thereby substantially avoiding reflections.

Still another object of the invention is to provide a switch which will always assume a given position in the event of any power failure to the end that a fail-safe arrangement may be provided.

These and many other objects and advantages of the present invention are attained in the preferred embodiment by providing a switch body of delta shape. Three wave guide passages pass normally inwardly from the flat faces of the structure to intersect in the central portion of the body at angles of substantially 120 with respect to each other. A vane is rotatably mounted at the line of intersection of the two walls of two of the passages so that swinging movement of the vane between a first and second position will alternately connect two of the passages to the third passage. The vane itself is of extremely small mass and very little power is required for effecting its rotation.

The preferred means for effecting rotation of the vane constitutes a rotary type solenoid which may be secured to the exterior portion of the body and coupled to the vane. Preferably resistance means is incorporated in the solenoid and arranged to be inserted in series with the solenoid coil automatically in response to movement of the vane to its energized position, so that the holding power required on the solenoid is minimized. A biasing spring may also be included to bias the vane to its unenergized position when the solenoid is tie-energized so that it will always assume this position to connect two of the three passages in the absence of any power By the above described delta shaped switch body construction, the optimum size is provided for switching between three wave guides and thus the desirable features of small size and mass are realized.

A better understanding of the invention will be had by now referring to a preferred embodiment thereof as shown in the accompanying drawings in which:

FIGURE 1 is an overall perspective view of the miniaturized wave guide switch showing three wave guides in position prior to connection to the switch body itself;

FIGURE 2 is a cross section of the switch body taken in the direction of the arrows 22 of FIGURE 1;

FIGURE 3 is another cross section of the switch body and solenoid drive therefor taken in the direction of the arrows 33 of FIGURES 1 and 2;

FIGURE 4 is a fragmentary cross section of a portion of the solenoid power unit taken in the direction of the arrows 4-4 of FIGURE 3;

FIGURE 5 is a schematic circuit diagram of the wiring for the solenoid power unit portion of the switch; and

FIGURE 6 illustrates in perspective a modified Vane structure for use in the switch body.

Referring to FIGURE 1, there is shown a delta shaped switch body 10 having three major flat faces 11, 12, and 13. These faces are respectively arranged to receive wave guides 14, 15 and 16 terminating in circular end flanges 14, 15', and 16', respectively. When the various wave guide flanges are secured to the faces of the switch body 10, electromagnetic energy in the wave guide 14 may be switched between the wave guide 15 and the wave guide 16. This switching operation may be'eifected by a simple manual knob, but in the preferred embodiment a rotary solenoid indicated generally by the arrow 17 is employed.

Referring now to the cross sectional View of FIGURE 2, it will be noted that the switch body 10 includes first, second, and third wave guide passages 18*, 19*, and 20 passing normally into the flat face to intersect at the cen tral portion of the body 10 at angles of to each other. Also shown on the front of each of the three faces of the body 10 are annular sealing type O-rings 21, 22, and 23, and annular cavity type high frequency chokes 24, 2,5, and 26, respectively. Because of the delta design, chokes in the three passages are root to root, the roots being separated by an extremely short electrical length d." The annular sealing O-n'ngs insure a moisture tight seal between the connected wave guides and the switch body while the choke construction minimizes power loss in the transfer of energy from the wave guides into the switch body.

In the embodiment shown in FIGURE 2, the switch is arranged to transfer energy from the first wave guide passage 18 to either one of the second and third wave guide passages 19 and 20. To this end there is provided a vane 27 secured to a shaft 28 within the body 10. The shaft 28 in turn is aligned with the intersection of the walls of the second and third passages 19 and 20 and is rotatably mounted at this point so that the vane 27 can swing from a first position as illustrated in solid lines through an arc of at least 60 to a second position illustrated in dotted lines. In the first, solid line position illustrated in FIG- URE 2, the first passage 18 is in communication with the third passage 20. In the second, dotted line position of FIGURE 2, the first passage is in communication with the second passage 19. If the vane is caused to oscillate back and forth, energy passing within the first passage 18 may be alternately transferred between the second and third passages to provide a lober.

Referring now to FIGURE 3, one means for effecting swinging movement of the shaft 28 and the vane 27 is illustrated. As shown, the lower end of the shaft 28 seats in a ball bearing support 29 near the floor of the body and the upper end protrudes through the top of the body and is maintained in vertical alignment by journal type bearings 30. The upper end of the shaft terminates in a pinion gear 31 within a lower cavity 32 of a solenoid body 33 secured to the switch body 10. A solenoid plunger pinion 34 is in threaded engagement with the pinion 31 and as shown is rigidly connected to the solenoid plunger member 35. The upper end of the plunger 35 may in turn be provided with spiral grooves 36 co-operating with stationary lands 37 projecting radially inwardly as an integral part of the solenoid body 33 so that up and down movement of the solenoid plunger 35 is converted into rotary movement to rotate the plunger pinion 34 and vane shaft pinion 31.

As shown in FIGURE 3, the extreme upper end of the plunger terminates in an insulated actuating rod 38 engaging the underside of a reed type contact arm 39 having one end secured to the solenoid body 33 as at 40 and its other end arranged to engage contact 41. In addition to the foregoing structure, there is provided an electrical resistance 42 annularly disposed about the solenoid body 33 connected in series with solenoid coils 43. Energizing leads 44 and 45 are shown passing into the solenoid body 33 to connect to the resistance 42 and coils.

Normally the shaft 28 and vane 27 are biased to the second or dotted line position illustrated in FIGURE 2 by a biasing spring of the coil type indicated at 46 in FIGURE 3. With particular reference to the cross section of FIGURE 4, it will be noted that in this instance the biasing coil spring has one end secured to the insulated rod 38 and its other end secured to the solenoid body 33 thereby applying a biasing force in a counter clockwise direction as viewed from the top of the plunger 35 as indicated by the arrow in FIGURE 4. As a consequence, the pinion 31 is biased in a clockwise direction to move the vane towards the dotted line position illustrated in FIGURE 2. In the embodiment of FIGURE 3, however, the solenoid plunger 35 and vane are shown in the position they assume when the coils 43 are energized. It will be noted that in this up or energized position of the plunger 35, the reed arm 39 is disengaged from the contact 41. When the solenoid coils 43 are de-energized, the plunger 35 and reed arm 39 assume the dotted line position illustrated in FIGURE 3 wherein the reed 39 is connected to the contact 41.

The actual wiring diagram for the contact 41, resistance 42, and solenoid coils 43 is illustrated in FIGURE 5. As shown, the power input lead 44 connects to one end of the resistance 42 and also to the reed arm 39. The other end of the resistance 42 in turn connects to one side of the solenoid coil 43 and also to the contact 41. The other side of the solenoid coil 43 connects to the other power input lead 45.

By the foregoing arrangement, when the reed arm 39 is closed on the contact 41, the resistance 42 is shunted out of the circuit and full power on the input leads 44 and 45 is applied directly to the solenoid coil 43. Upon energization of the solenoid coil 43 to move the plunger 35 upwardly, the insulating rod 38 will move the reed arm 39 upwardly to disengage it from the contact 41. As a result, the resistance 42 is placed in series with the coil 43. The provision of the series resistance will reduce the power supplied to the solenoid coil to a value just sufficient to hold the plunger 35 in its up position.

The operation of the overall switch will be evident from the foregoing description. In the absence of any electrical energy supplied to the leads 44 and 45, the biasing spring 46 will hold the shaft 28 and vane 27 in the second dotted line position illustrated in FIGURE 2. In such position, electromagnetic energy passing into the first wave guide passage 18 will pass out the second wave guide passage 19. Upon energization of the coils 43 by applying power to the input leads 44 and 45, the solenoid plunger 35 will be moved upwardly and this movement will be translated into a clockwise rotation as viewed from the top to rotate the shaft pinion 31 in a counter-clockwise direction. This counter-clockwise movement rotates the shaft and vane 27 from the dotted line to the solid line position shown in FIGURE 2. Simultaneously with the upward movement of the plunger 35, the reed 39 is disengaged from the contact 41 so that the resistance 42 is placed in series with the coil 43 and thus minimum holding power is required as explained heretofore.

With the vane in the solid line position, as illustrated in FIGURE 2, ultra high frequency energy in the passage 18 will now pass out the third passage 20 as indicated by the solid arrows. When the coils 43 are de-energized, the spring 46 will return the vane from the solid to the dotted line position.

An important advantage of the foregoing type of construction is that the vane 27 itself which is of extremely small mass actually effects the entire switching operation. Thus, very little energy is required to rotate the vane through the required 60 to effect the switching operation. Further, the response time is extremely short.

In order that the isolated passage may be terminated in an impedance corresponding as closely as possible to its characteristic impedance to eliminate reflections, the vane may be modified slightly as illustrated in FIGURE 6. As shown a vane 47 is secured to a shaft 28' similar to the shaft 28 described in the previous embodiment. The vane 47, includes on its opposite surfaces triangular shaped members 48 and 49, respectively. These members are so shaped and spaced with respect to each other over the surface that when positioned to intercept normally electromagnetic energy passing down the wave guide closed off by the vane, the characteristic impedance of the guide is substantially provided. In this one vane position, the corresponding members on the opposite side are not directed normally to the direction of any electromagnetic radiation present and will not appreciably affect the same.

For example, when the vane illustrated in FIGURE 6 is incorporated in the switch body of FIGURE 2, the members 49 will terminate the second passage 19 in substantially its characteristic impedance While the members 48 will not appreciably affect flow of energy between the passage 18 and passage 20. When the vane is moved to the dotted line position, the members 48 will then terminate the passage 20 in substantially its characteristic impedance while the vanes 49 will not appreciably alfect transfer of energy from the passage 18 to the passage 19.

From the foregoing description, it will be evident that the present invention provides a greatly improved Wave guide switch. Not only are size and weight minimal as a consequence of the delta design, but the simplified switching vane structure enables switching to take place under fully energized conditions with a maximum mismatch not exceeding 2:1. By connecting the various guides 14, 15, and 16 such that isolation of the passages 18 and 20 and connection of the passages 18 and 19 constitute a safe condition, the switch will always assume this condition in the event of power failure.

One of the most important features of the invention resides in the delta shape of the switch body which not only results in a compact structure as heretofore pointed out, but enables a switching vane of extremely short electrical width to be used. As a consequence, the connected passages appear continuous with respect to electromagnetic energy passing therethrough. In other words, the pivot line of the vane and vane edge portion engaging the passage edge are electrically spaced only a fraction of a wave length so that substantially no reflections occur.

Modifications falling within the scope and spirit of this invention will occur to those skilled in the art. The wave guide switch is, therefore, not to be thought of as limited to the exact embodiments shown merely for illustrative purposes.

What is claimed is:

1. A wave guide switch comprising, in combination: a delta shaped body having first, second, and third wave guide passages passing normally inwardly from the fiat faces of said body respectively to intersect in the central portion of said body at angles of 120 with respect to each other; a vane of dimensions corresponding to the internal dimensions of said wave guide passages; drive means secured to one edge of said vane and rotatably mounted at the line of intersection of the two walls of said second and third passages, whereby swinging movement of said vane back and forth through an angle of 60 in response to rotation of said drive means alternately connects said second and third passages to said first passage, the plane of said vane forming equal angles with said first passage and the second and third passages when respectively connected to said first passage.

2. The subject matter of claim 1, including: biasing means coupled between said drive means and body to bias said drive means in a direction to swing said vane to one position; and electromagnetic means secured to said body and coupled to said drive means for overcoming said biasing means to swing said vane to its alternate position upon energization thereof.

3. The subject matter of claim 2, in which said electromagnetic means comprises a rotary solenoid; an electrical resistance connected in series with said solenoid; and normally closed contact means shunting said resistance and responsive to movement of said drive means upon energization of said coil to open.

4. A wave guide switch comprising, in combination: a delta shaped switch body having three flat major faces and first, second, and third rectangular wave guide passages passing normally inwardly from said faces respectively to intersect in the central portion of said body at angles of 120 with respect to each other; a vane of rectangular dimensions corresponding to the rectangular cross sectional dimensions of said wave guide passages; a shaft secured to one longitudinal edge of said vane; means in said body rotatably mounting said shaft in alignment with the line of intersection of the two adjacent walls of said second and third passages so that said vane is movable over an arc of from a first position closing the inner end of said second wave guide passage to a second position closing the inner end of said third wave guide passage; a rotary solenoid secured to said body exterior of said passages and coupled to said shaft for rotating said shaft from said second to said first position; and biasing means holding said vane in said second position when said rotary solenoid is de-energized.

5. The subject matter of claim 4, including an electrical resistance; and contact means for placing said resistance in series with said solenoid upon movement of said vane from said second to said first position.

6. The subject matter of claim 4, in Which said vane includes triangular shaped radiation absorbing members extending normally from its opposite surfaces whereby the inner ends of said second and third passages are ter minated in substantially their characteristic impedances when said vane is in said first and second positions respectively.

7. The subject matter of claim 4, in which each of said three flat major faces includes annular grooves surrounding said passages and in communication with the entrance portion of said passages at said faces, said grooves projecting normally inwardly and terminating in said body to provide high frequency chokes when connecting wave guide flanges are secured to said major faces to pass energy through said switch.

8. The subject matter of claim 7, in which the distance between said entrance portions to said passages and the width of said vane are less than a wave length.

References Cited in the file of this patent UNITED STATES PATENTS 2,865,005 Kuecken Dec. 16, 1958 2,917,719 Brown Dec. 15, 1959 OTHER REFERENCES Microwave Transmission Circuits (Ragan), McGraw Hill Book Co., New York, 1948 (pages 203-207 relied on). 

